IllegalStateException: Feeder is now empty, stopping engine


with snapshot from the 24th,

If I have the following simulation which (for test case purposes only, normally it would find file paths) doesn’t find any data,
Gatling fails with the errors below.

I am not totally sure why it throws the exception as with small changes to the code like removing the filter it appears to avoid the error. It’s not blocking me but thought it worth reporting the error.


def matchesExtension(file: File, extensions: Set[String]) =

extensions.exists(ext => file.getName.toLowerCase.contains("." + ext))

def findPaths(root: String, extensions: Set[String]): Array[Map[String, String]] =

findFiles(new File(root))

.filter(matchesExtension(_, extensions))

.map(f => Map(“path” → f.getPath.drop(root.length)))


def findFiles(f: File): Stream[File] = f #:: (Stream.empty)

val data = findPaths("/nowhere", Set(“txt”, “out”, “logs”)).random

val request = exec(



val scn = scenario(“requests”)




Simulation ASimulation started…

That’s the standard feeder behavior: it stops the simulation once the feeder is empty.

ok thanks